Magnifications
and
Exposure
Factors
A reading
of
3.2 on
the
magnification
scale
indicates
that
a magnification
of
1/ 3.2
will
be
obtained.
When
metering
with
an
independent
light
meter, exposure must be increased
as
indicated in
the
chart
below
. Exposure
com
-
pensation is
not
required
as
such
when
using
the
accessory
TTL
metering Pentaprism Finder.
However,
film
reciprocity
varies
with
different
films, and required compensation should be
made
accordingly
in compliance
with
the
manufacturer's guide,
with
or
without
TTL
metering.
In close-up
work
,
the
depth
of
,field is gener-
ally shallow. Best results can be obtained
by
preselecting the lens aperture.
However
,
as
inbetween
shutter
speeds are
not
available,
the
aperture should be opened up an additional
1/2
stop
at the 1.5 magnification
sett
ing.
At
the
" 2" setting,
lower
the
shutter
speed 1
step,
or
open up the aperture a full extra
stop
.
SMC MACRO TAKUMAR EXPOSURE FACTORS
MAGNIFICATION
EX
POSURE
FACTOR
Why
Exposure
Compensation
is Necessary
With
close-ups,
the
volume
of
light
reaching
the
film
plane decreases
by
half in
porportion
to
magnification
increase.
TTL
meters over-
come
this
problem
by
measuring
the
total
amount
of
light
entering
the
lens.
However
,
unless
the
meter
is located
behind
the lens,
this
loss requires
compensation
.
Irregularities
in
Coior
Film
With
time
exposures in excess
of
1 sec.
using
color
film
,
certainirregularites
in
film
response
often
lead
to
undereposure
; thus,
exposure
times
often
have
to
be increased
at
slow
speeds.
Moreover
,
with
most
reverse
color
films,
color
reproduct
i
on
character
istics
change
with
exposures
longer
than
1/ 10
second.
However
,
irregularitie
s can be
avoided
by
using
CC
filters
. Refer
to
guides
published
by
the
respective
manufacturer
for
exact data
concerning
color
reproduction
characteristics and required
compen
sation
for
the
film
in use.
23
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